diff --git a/include/security/pam_types.h b/include/security/pam_types.h
index 2cafa01..1ec6400 100644
--- a/include/security/pam_types.h
+++ b/include/security/pam_types.h
@@ -31,12 +31,14 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $P4: //depot/projects/openpam/include/security/pam_types.h#7 $
+ * $P4: //depot/projects/openpam/include/security/pam_types.h#8 $
  */
 
 #ifndef _PAM_TYPES_H_INCLUDED
 #define _PAM_TYPES_H_INCLUDED
 
+#include <sys/types.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif